SVG graphics

"Additionally, SVG is currently treated as a document format, not an image format. This means that SVG will only work in the following contexts: as an <object> or <embed> element (although it should be noted that the <embed> element is deprecated), as the specific document displayed in the browser window or in a frame in that window, or as an integrated part of an XHTML document using multiple namespaces."

This is a CSS tutorial, not the right context for these details of HTML markup.